iOs receivedData from NSURLConnection is nil - objective-c

Question

I was wondering if anyone could point out why I'm not able to capture a web reply. My NSLog shows that my [NSMutableData receivedData] has a length of 0 the entire run of the connection. The script that I hit when I click my login button returns a string. My NSLog result is pasted below, and after that I've pasted both the .h and .m files that I have.
NSLog Result
2012-11-28 23:35:22.083 [12548:c07] Clicked on button_login
2012-11-28 23:35:22.090 [12548:c07] theConnection is succesful
2012-11-28 23:35:22.289 [12548:c07] didReceiveResponse
2012-11-28 23:35:22.290 [12548:c07] didReceiveData
2012-11-28 23:35:22.290 [12548:c07] 0
2012-11-28 23:35:22.290 [12548:c07] connectionDidFinishLoading
2012-11-28 23:35:22.290 [12548:c07] 0
ViewController.h
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController
// Create an Action for the button.
- (IBAction)button_login:(id)sender;
// Add property declaration.
#property (nonatomic,assign) NSMutableData *receivedData;
#end
ViewController.m
#import ViewController.h
#interface ViewController ()
#end
#implementation ViewController
#synthesize receivedData;
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
NSLog(#"didReceiveResponse");
[receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
NSLog(#"didReceiveData");
[receivedData appendData:data];
NSLog(#"%d",[receivedData length]);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(#"connectionDidFinishLoading");
NSLog(#"%d",[receivedData length]);
}
- (IBAction)button_login:(id)sender {
NSLog(#"Clicked on button_login");
NSString *loginScriptURL = [NSString stringWithFormat:#"http://www.website.com/app/scripts/login.php?"];
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:loginScriptURL]];
NSString *postString = [NSString stringWithFormat:#"&paramUsername=user&paramPassword=pass"];
NSData *postData = [postString dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
[theRequest setHTTPMethod:#"POST"];
[theRequest setHTTPBody:postData];
// Create the actual connection using the request.
NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
// Capture the response
if (theConnection) {
NSLog(#"theConnection is succesful");
} else {
NSLog(#"theConnection failed");
}
}
#end

Answer 1

The issue is you are not initializing the receivedData instance. Just change your property like:
#property (nonatomic, retain) NSMutableData *receivedData;
And change the methods like:
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
NSLog(#"didReceiveResponse");
[self.receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
NSLog(#"didReceiveData");
[self.receivedData appendData:data];
NSLog(#"%d",[receivedData length]);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSLog(#"connectionDidFinishLoading");
NSLog(#"%d",[receivedData length]);
}
- (IBAction)button_login:(id)sender
{
NSLog(#"Clicked on button_login");
NSString *loginScriptURL = [NSString stringWithFormat:#"http://www.website.com/app/scripts/login.php?"];
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:loginScriptURL]];
NSString *postString = [NSString stringWithFormat:#"&paramUsername=user&paramPassword=pass"];
NSData *postData = [postString dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
[theRequest setHTTPMethod:#"POST"];
[theRequest setHTTPBody:postData];
// Create the actual connection using the request.
NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
// Capture the response
if (theConnection)
{
NSLog(#"theConnection is succesful");
self.receivedData = [NSMutableData data];
} else
{
NSLog(#"theConnection failed");
}
}

Answer 2

Please try "%i" instead of %d in nslog

Answer 3

You can try the following code May be help you.
- (IBAction)button_login:(id)sender {
NSLog(#"Clicked on button_login");
NSMutableDictionary *dictionnary = [NSMutableDictionary dictionary];
[dictionnary setObject:#"user" forKey:#"Username"];
[dictionnary setObject:#"pass" forKey:#"Password"];
NSError *error = nil;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dictionnary
options:kNilOptions
error:&error];
NSString *urlString = #"Sample URL";
NSURL *url = [NSURL URLWithString:urlString];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:#"POST"];
[request setHTTPBody:jsonData];
NSURLResponse *response = NULL;
NSError *requestError = NULL;
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&requestError];
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding] ;
NSLog(#"%#", responseString);
}
if it is a GET Request then, can you try link : /login.php?username=admin&password=1212‌​3
- (IBAction)button_login:(id)sender {
NSLog(#"Clicked on button_login");
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"/login.php?username=adm‌​in&password=1212‌​3"]];
// Perform request and get JSON as a NSData object
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSLog(#"response=%#",response );
}
and use this code.